Area Forecast Discussion
Issued by NWS Wilmington, NC

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259
FXUS62 KILM 141636
AFDILM

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE WILMINGTON NC
1135 AM EST SUN FEB 14 2016

.SYNOPSIS...
ARCTIC HIGH PRESSURE REMAINS IN PLACE TODAY AND WILL BE SLOW
TO ERODE TOMORROW AS IT GETS OVERRUN WITH MOISTURE. A SOAKING RAIN
IS EXPECTED MONDAY NIGHT INTO EARLY TUESDAY.  DRY AND SEASONABLE
WEATHER IS EXPECTED FOR THE REMAINDER OF NEXT WEEK.

&&

.NEAR TERM /THROUGH TONIGHT/...
AS OF 930 AM SUNDAY...THE AFTERNOON FORECAST IS MORE OR LESS
STRAIGHT FORWARD. THE ARCTIC HIGH WILL SHIFT EAST...MOVING OFF
THE NORTHEAST COAST THIS EVENING. COLD ADVECTION HAS ALL BUT ENDED
WITH A PERIOD OF NEUTRAL ADVECTION SETTING UP FOR TODAY. MOISTURE
ALOFT SPREADING EAST IN THE PROGRESSIVE MID LEVEL FLOW WILL LEAD
TO A STEADY INCREASE IN CLOUD COVER AHEAD OF A SOUTHERN STREAM
SYSTEM THAT WILL BECOME MORE DEFINED ALONG THE GULF COAST
OVERNIGHT. TEMPERATURES THIS MORNING ENDED UP A LITTLE WARMER
THAN EXPECTED...PARTLY DUE TO PASSING CIRRUS AND PARTLY DUE TO
HIGHER BOUNDARY LAYER MOISTURE. DID NOT MAKE A LOT OF CHANGES TO
THE FORECAST FOR TODAY BUT DID BUMP UP HIGHS A DEGREE OR TWO IN
SOME AREAS...ESPECIALLY ALONG THE COAST WHERE MORE SUBSTANTIAL
CLOUD COVER WILL TAKE A LITTLE LONGER TO DEVELOP.

THE MORE DIFFICULT FORECAST ISSUE REMAINS PRECIP POTENTIAL (BOTH
CHANCES AND LIQUID VS FROZEN) OVERNIGHT AND HOW QUICKLY THE
SURFACE LAYER WARMS/MOISTENS. WHILE THERE IS STILL POTENTIAL FOR
SOME LIGHT ISOLATED ICING ACROSS FAR INLAND AREAS AS THE PERIOD
COMES TO AN END CONFIDENCE REMAINS VERY LOW. HAVE NO PLANS TO MAKE
ANY CHANGES TO PREVIOUS FORECAST THIS MORNING BUT WITH THE LATEST
DATA STARTING TO ROLL HOPE TO HAVE A BETTER IDEA OF HOW THE EVENT
MIGHT PLAY OUT LATER THIS AFTERNOON.

&&

.SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/...
AS OF 3 AM SUNDAY...ARCTIC HIGH PRESSURE NOT SO WILLING TO BE
ERODED AS PREVIOUSLY THOUGHT. IN FACT THERE EXISTS UP TO A 10
DEGREE DIFFERENCE IN FORECAST HIGHS INLAND FOR MONDAY. A VAST
MAJORITY OF TIME WHEN THIS IS THE CASE THE COLDER GUIDANCE ENDS UP
BEING CORRECT. AS SUCH THE FORECAST HAS BEEN NUDGED TOWARDS THE
COOLER NUMBERS. GIVEN THE THREAT FOR PRECIP TO MANIFEST AS
FREEZING RAIN OVER DEEP INTERIOR COUNTIES DURING THE MORNING THESE
DIFFERENCES ARE QUITE CRITICAL. HAVING SAID THAT, THE WINDOW
DURING WHICH ZR IS POSSIBLE REMAINS ONE OF LOW POPS AND MINIMAL
QPF SINCE FOR THE SAME REASON THE HIGH IS SLOW TO MOVE OUT IT
SHOULD ALSO BE SLOW TO SATURATE. A MODEL QPF DIFFERENCE BETWEEN
THE GFS AND WRF IS THAT THE LATTER LIKES A WETTER COAST MONDAY
MORNING ASSOCIATED WITH THE WELL-FORMED SURFACE TROUGH. GIVEN THAT
MOST OF MONDAY`S FORCING IS IN THE LOW LEVELS AND FORECAST
SOUNDINGS LOOK PRETTY DRY ABOVE 800 (OR IN SOME CASES 900) MB THIS
SEEMS PLAUSIBLE.

THE WEDGE FINALLY DOES BREAK MONDAY NIGHT AND EXPECT TEMPERATURES TO
RISE MONDAY NIGHT, IN SOME PLACES DRAMATICALLY (LOW 60S BY
MORNING?). THE LATTER HALF OF MONDAY NIGHT ALSO REPRESENTS WHEN THE
APPROACHING SYSTEMS MID LEVEL ASCENT FORCEFULLY KICKS IN. AT THIS
TIME EXPECT MODERATE TO OCCASIONALLY HEAVY RAIN BREAKING OUT ACROSS
THE REGION. COULD NOT PINPOINT HEAVIEST RAINFALL POTENTIAL SINCE
HEIGHT FALLS AND PVA STRONGEST INLAND BUT COASTAL LOCATIONS ESP SC
MAY SEE ELEVATED INSTABILITY DEVELOP, WHICH WILL THEN MOVE INTO CAPE
FEAR TUESDAY MORNING. THE ENTIRE MOISTURE PLUME IS SHUNTED DECIDEDLY
OFF THE COAST BY 18Z TUESDAY AND THERE WILL BE A BRIEF PERIOD OF
GUSTY WINDS AS THE LOW LEVEL JET RELAXES. SPEAKING OF, IT IS THIS
STRONG LLJ THAT WILL YIELD A DAMAGING WIND THREAT ALONG THE COAST A
FEW HOURS PRIOR TO AND FOLLOWING SUNRISE. SPC CONTINUES TO CAP THIS
RISK AT MARGINAL. TUESDAY NIGHTS COLD ADVECTION LOOKS PRETTY LAZY
AND SO THOUGH NOT AS MILD AS MONDAY  NIGHT LOW TEMPERATURES WILL
REMAIN ABOVE CLIMATOLOGY.

&&

.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
AS OF 3 AM SUNDAY... THE LONG TERM WILL OFFER UP RAIN-FREE
WEATHER. WEDNESDAY WILL BE QUITE SEASONABLE WITH BROAD, LOW
AMPLITUDE UPPER TROUGHINESS ONLY DRIVING A WEAK HIGH INTO THE MS
VALLEY. UPPER TROUGH DEEPENS SLIGHTLY OFF THE EAST COAST DRIVING A
LOW LEVEL THERMAL TROUGH INTO SAME FOR A SLIGHT COOLDOWN. HIGH
PRESSURE GROWS AND STRENGTHENS UP AND DOWN THE EAST COAST FRIDAY
AND SATURDAY FOR A WARMUP.

&&

.AVIATION /18Z SUNDAY THROUGH FRIDAY/...
AS OF 18Z...QUITE A BIT OF UNCERTAINTY ON THE BACK END OF THIS
FORECAST WITH RESPECT TO TIMING AND INTENSITY OF THE PRECIP AS
WELL AS PRECIP TYPE. INCREASING HIGH CLOUDS THIS AFTERNOON IN
ADVANCE OF THE NEXT SYSTEM. NORTHEAST FLOW IS EXPECTED THROUGH
THE EVENING HOURS. OVERNIGHT...LIGHT PRECIP WILL BEGIN TO FORM
AS ISENTROPIC LIFT BEGINS. MODELS DO NOT SHOW MUCH MID LEVEL
MOISTURE SO THINK PRECIP WILL BE QUITE LIGHT. MOISTURE PROFILES
SHOW A LOT OF WARM AIR ADVECTING IN JUST ABOVE THE SURFACE...HOWEVER
SURFACE TEMPERATURES AT THE INLAND TERMINALS WILL LIKELY BE
BELOW FREEZING AT THE ONSET...SO LIGHT FREEZING RAIN IS
EXPECTED...EMPHASIS ON LIGHT. ALONG THE COAST...A PRETTY GOOD
COASTAL TROUGH IS EXPECTED WITH RAIN BEGINNING AFTER DAYBREAK.
THE INLAND TERMINALS WILL BE IN THE WEDGE ALL DAY...HOWEVER TEMPS
ARE EXPECTED TO RISE ABOVE FREEZING AROUND MID MORNING...SO
TRANSITION TO ALL RAIN.

EXTENDED OUTLOOK...POSSIBLE MVFR/IFR CONDITIONS IN RAIN/SHOWERS
MONDAY AFTERNOON THROUGH TUESDAY MORNING. BECOMING VFR TUESDAY
AFTERNOON THROUGH FRIDAY.

&&

.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 10 AM SUNDAY...NORTHEAST FLOW WILL GRADUALLY WEAKEN TODAY
AND GAIN MORE OF AN EASTERLY COMPONENT AS HIGH PRESSURE TO THE
NORTHEAST SLIDES EAST. WINDS WILL REMAIN 15 TO 20 KT INTO THE
AFTERNOON BEFORE DROPPING TO 10 TO 15 KT THIS EVENING. DEVELOPMENT
OF COASTAL TROUGH OVERNIGHT WILL LEAD TO FURTHER WEAKENING OF
WINDS WITH EAST OR EVEN SOUTHEAST WINDS DEVELOPING AS THE PERIOD
ENDS. SEAS RANGING FROM 2 TO 5 FT THIS MORNING WILL GRADUALLY
DECREASE DURING THE AFTERNOON AND EVENING HOURS.

SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/...
AS OF 3 AM SUNDAY...THE ENTIRE FORECAST AREA WILL LIKELY BE HOME
TO A STALLED OUT FRONTAL BOUNDARY PARALLELING THE COAST. THIS
FRONT WILL BE TRYING AND FAILING TO ADVANCE INLAND INTO WHAT
REMAINS OF THE ARCTIC WEDGE. JUST EAST OF THE FRONT A MODERATELY
STRONG GRADIENT AND LONG EASTERLY FETCH WILL DEVELOP SO EVEN
THOUGH THE FRONT MAY YIELD A DECREASE IN WINDS THE SEAS WILL BE
GROWING TO ADVISORY LEVELS. MONDAY NIGHT AS THE WEDGE DETERIORATES
AND THE BOUNDARY MOVES ASHORE THESE GRADIENT WINDS WILL ENTER THE
MARINE ZONES WITH GUSTO. A LATE NIGHT APPROACH OF A STRONGLY
FORCED COLD FRONT WILL VEER THE WINDS AND FURTHER TIGHTEN THE
GRADIENT. LOW LEVEL WIND FIELDS CERTAINLY SUPPORT GALE FORCE GUSTS
IN THE ABSENCE OF STABILITY ARGUMENTS. HOWEVER GIVEN THAT A VERY
WARM AIRMASS WILL BE IN PLACE MOVING OVER THE MUCH COOLER SSTS
VERTICAL MIXING WILL BE COMPROMISED. CURRENT FORECAST CONFINES A
FEW GALE FORCE GUSTS TO JUST A SMALL PART OF THE OUTER REACHES OF
NC WATERS. TUESDAY MIDDAY FRONTAL PASSAGE TO BRING AN ABRUPT TURN
TO THE WEST AND A MARKED DECREASE IN WIND SPEED. ADVISORY LEVEL
SEAS LIKELY NEEDING TIL TUESDAY NIGHT TO SETTLE BELOW THRESHOLDS.

LONG TERM /WEDNESDAY THROUGH THURSDAY/...
AS OF 3 AM SUNDAY...WEST TO NORTHWEST FLOW ON SUNDAY AS HIGH
PRESSURE SETTLES UP AND DOWN THE MS VALLEY WITH NO STRONG
GRADIENTS ASSOCIATED WITH THE ANTICYCLONE. LIGHT WIND AND
DIMINISHING SWELL ENERGY LEADS TO ABATING SEAS. THE HIGH GROWS,
STRENGTHENS, AND MOVES EASTWARD ON THURSDAY. LOCALLY WINDS WILL
TURN MORE TO THE NORTH AND THE GRADIENT SHOULD ACTUALLY SLACKEN
ESP LATE IN THE DAY AS RIDGE AXIS NEARS. SEAS DROP IN HEIGHT BY
ABOUT A FOOT.

&&

.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...COASTAL FLOOD ADVISORY FROM 1 PM TO 4 PM EST THIS AFTERNOON
     FOR NCZ107.
MARINE...NONE.

&&

$$

NEAR TERM...III
SHORT TERM...MBB
LONG TERM...MBB
AVIATION...DL



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